Dry drilling and core acquisition system

ABSTRACT

A rotary dry drilling system comprises a surface mounted drill having a drill bit and a drill bit driver rotationally connected by a hollow drill string. There is included core sample capture means adapted to travel from the head of the drill string to the tail of the drill string. The system also comprises an auger for removing cuttings from a comminution zone and cuttings fluidization means to facilitate transport of cuttings from the comminution zone to the auger. Once the cuttings are removed by the auger they are collected and transported to the surface for disposal.

FIELD OF THE INVENTION

The present invention relates generally to the field of core boring and more particularly to a dry drilling and core capture device.

BACKGROUND OF THE INVENTION

Traditional sample recovery systems rely heavily upon the use of water to flush the cuttings away from the rock/bit interface or comminution zone. Water pressure is also used to deliver the core capture device to the bottom of the hole and allows the dogging mechanism to latch properly. This technology only works on consolidated material. Unconsolidated materials would normally be flushed away from the hole thus preventing the capture of a sample.

Lunar drilling will be a dry drill scenario. Fluids will not likely be available to flush away the cuttings from the comminution zone. Additionally, there is a desire to capture unconsolidated material rather than flush it away. Thus conventional drilling cannot be used.

There is a need for an apparatus that permits dry drilling and core capture in environments where fluid will not likely be available.

SUMMARY OF THE INVENTION

The apparatus of this invention is designed for dry drilling and core capture and so solves the need stated above. The apparatus is a rotary dry drilling system comprising a surface mounted drill having a drill bit and drill bit driving means rotationally connected through a hollow drill string to the drill bit for drilling a bore through rock to obtain a core sample of the rock. The drill string has a head and a tail. The core sampler is adapted to travel from the head of the drill string to the tail of the drill string to capture the core sample of rock. There is also included auger means connected to the drill bit for removing cuttings from the drill comminution zone and transporting the cuttings up-hole. To ensure that the cuttings move smoothly up-hole and do not foul the drilling operation there is provided with the system a cuttings fluidization means connected to the head of the drill string to facilitate transport of cuttings from the comminution zone to the auger means. A cuttings management means is connected to the drill string for collecting and transporting cuttings to the surface. The core sampler or core capture device comprises a rotating gate assembly having a first open position and a second closed position; a core tube adapted to receive a core sample; an activation tube coaxial with the core tube and surrounding the core tube. The activation tube is adapted to mechanically engage the rotating gate assembly thereby moving it from the first open position to the second closed position.

A screw cap is included and adapted to engage the activation tube and transmit rotational movement from the drill motor to the activation tube so that the activation tube is forced into engagement with the gate assembly. The gate assembly comprises a gate assembly housing fixed to the bottom end of the core tube to house a rotating gate body. The rotating gate body comprises a first disc and a second disc. Each of the discs has an axis and they are co-axial. The first disc and second disc are jointed by a member between the respective rims of the first and second disc.

The invention is more fully understood by referring to the following diagrams and detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a cross-sectional side view of the down-hole end of a drill string of one example of the invention.

FIG. 2 is an assembly diagram of the components of the core capture device of another example of the invention.

FIG. 3 is a more detailed diagram of the components of the core capture device of the example shown in FIG. 2.

FIG. 4 illustrates the activation tube of one example of the invention.

FIG. 5A illustrates the bottom portion of the activation tube illustrated in FIG. 4.

FIG. 5B illustrates the activation cap of one example of the invention.

FIG. 5C illustrates the auger tube of one example of the invention.

FIG. 6 illustrates the bottom portion of the core capture tube in one example of the invention.

FIG. 7 illustrates the first and second side plates of one example of the invention.

FIG. 8 illustrates major sub-systems of the mechanical control system of one example of the invention.

FIG. 9 illustrates the wireline of one example of the invention.

FIG. 10 illustrates the wireline in three modes of operation.

FIG. 11 illustrates the overshot mechanism of one example of the invention.

FIG. 12 illustrates the port control mechanism of one example of the invention.

FIG. 12A illustrates the outer port control sleeve of the example of FIG. 12.

FIG. 12B illustrates the inner port control sleeve of the example of FIG. 12.

FIG. 13 illustrates the bailings bucket of one example of the invention.

FIG. 14 illustrates the bailings bucket of the example of the invention of FIG. 13.

FIG. 15 illustrates the anti-contamination wipers of one example of the invention.

FIG. 16 illustrates the anti-contamination wipers of the same example of the invention as FIG. 15.

FIG. 17 illustrates the location of a second anti-contamination wiper of one example of the invention.

FIG. 18 shows in exploded view the fluidizer of one example of the invention.

FIG. 19 illustrates the circular bottom housing of the example of FIG. 18.

FIG. 20 illustrates the flat top cap of the example of FIG. 18.

FIG. 21 illustrates the cam of the fluidizer of FIG. 18.

FIG. 22 illustrates the hinge member of the fluidizer of FIG. 18.

FIG. 23 illustrates the hammer of the fluidizer of FIG. 18.

FIG. 24 illustrates the ring member of the anvil of the fluidizer of FIG. 18.

FIG. 25 illustrates the cam bearing block of the fluidizer of FIG. 18.

FIG. 26 illustrates the spring cap of the fluidizer of FIG. 18.

DETAILED DESCRIPTION OF THE INVENTION The Core Capture Device

FIG. 1 shows a cross-sectional side view of the down-hole end of a drilling string (8) illustrating the core capture device (10) constructed in accordance with one example of the invention. The core capture device (10) is comprised of a core capture tube (12) contained within an activation tube (14) which in turn is contained within an auger tube (16). The core capture tube contains the core capture device. The activation tube transmits forces to activate and deactivate the core capture device as more fully explained herein. The forces are transmitted by way of a wire string and clutches through the drill string. The auger tube carries cuttings from the communition zone up the drill string and away from the drill bit (18) which is located at the end of the drill string and the auger tube.

The core capture device includes a core capture scoop (20) located at the down-hole end of the core capture tube (12). The scoop is adapted to capture a sample of a drill core (24) formed as the drill bit (18) progresses downward into a rock formation (22). As the core grows longer, it moves into the orifice (25) of the drill string and into the core capture device (20). Sensors on the drill string are able to measure just how much core is available for capture and when the core capture device should be activated.

FIG. 2 is an assembly diagram of the components of the core capture device (10), the core capture tube housing the core capture device and the activation tube. The core capture tube (12) consists of a lower housing portion (24) attached below an upper portion (26). The lower housing portion (24) houses the core capture device (10). Placed over the core capture tube (12), and in mechanical communication with the core capture device is the activation tube (28) composed of a bottom portion (30) and an upper portion (32). An activation cap (34) is fixed to the upper end (36) of the upper portion (32) of the activation tube.

FIG. 3 is a more detailed diagram of the components comprising the top end assembly (38) of the core capture device. The components are shown in a transparent view so that their inner features are illustrated and an appreciation of how they are assembled can be gained. The components of the top end assembly (38) consist of the core capture tube upper portion (26) over which is placed the upper portion (32) of the activation tube. The activation cap (34) is placed over the top end (40) of the activation tube upper portion (32). The top end (42) of the core capture tube upper portion (26) ends in a cylindrical projection (44) having a threaded aperture (46) angled inward at its centre. As can be seen from the dashed transparency lines, the core capture tube upper portion (26) is adapted to fit within the upper portion (32) of the activation tube such that the lower bell portion (50) of the core capture tube upper portion fits within the first void (52) of the upper portion of the activation tube (32). The cylindrical upper section (54) of the core capture tube upper portion (26) passes through the first void (52) and second void (56) of the upper portion (32) of the activation tube and into the first void (58) of the activation cap (34). The first void (58) of the activation cap is separated from the second void (60) of the activation cap by a throat (62) into which the inside threaded cylindrical projection (44) is set. In its assembled configuration, the top portion (64) of the upper portion of the activation tube (32) is set within the first void (58) of the activation cap (34) so that the top end (40) of the activation tube upper portion abuts against the inner top surface (66) of the first void (58) of the activation cap. In its assembled configuration the top end (40) of the core capture tube upper portion (32) abuts against the upper inner surface (66) of the first void (58). To avoid wear, washer (68) is placed on the top end (42) between it and the inner surface (66). In one embodiment of the invention the washer (68) is made from bronze. Inside threaded cylindrical projection (44) is disposed within throat (62) so that the top end (70) of the projection (44) is above the bottom surface (72) of the second void (60) of the activation cap. At least one washer (74) and perhaps two washers (74) and (76) are placed over the projection and a cap screw (78) is used to fix the activation cap (34) to the core capture tube. In one embodiment of the invention the washers are made of bronze.

FIG. 4 shows four views: A (side—partial cut away), B (bottom end), C (bottom perspective) and D (top perspective) of the upper portion (32) of the activation tube. The upper portion (32) of the activation tube has a top section (64) and a bottom section (82). The top section (64) has an outside diameter (84) that is wider than the outside diameter (86) of the bottom section (82). The height (90) of the top end is shorter than the height (92) of the bottom end.

FIG. 5A there are shows four views—A (side view), B (top view), C (perspective view) and D (bottom view) of the bottom portion (30) of the activation tube. The bottom portion (82) of the upper portion (32 in FIG. 4) of the activation tube has a bottom threaded end (94) adapted for engagement with the threaded portion (100) of the top end (80) of the bottom portion (30) of the activation tube. The void (98) is configured so that the top end (80) of the bottom portion of the activation tube (30) fits within space (102) and the top edge (104) abuts against interior shoulder (106) of space (102). Void (98) and throat (110) are dimensioned to accept the upper portion (26) of the core capture tube (26 FIG. 2). The top end (80) of the bottom portion (30) is threaded to permit secure attachment to the bottom (94) end of the top portion (32) of the activation tube. Below the top end (80) are a middle interior section (111) and a bottom interior section (112). The middle and bottom interior sections are configured to accept the lower portion (24) of the core capture tube that contains the core capture device (10). The bottom section (112) of the lower portion of the activation tube includes a first guide way (114) and a second guide way (116). These guide ways are mechanically linked to first and second lugs on the sampling gate of the core capture device within the bottom portion of core capture tube as more fully explained below.

FIG. 5B shows two views—A (assembled) and (B) cross-section of the activation tube (28) of the invention comprising the lower portion (30) and the upper portion (32) and the activation cap (34). The cross-sectional view (B) illustrates the core capture tube (12) containing the core capture device (10). Attached to the top end of the activation cap is the bailings bucket (302) which is more fully illustrated and explained below.

FIG. 5C shows two views of the auger tube (500) of the invention in side view (A) and 10 cross-sectional view (B). The activation tube is set within the auger tube. Cuttings from the bit end (504) are forced up the drill hole and away from the bit by the rotational action of the auger tube. Once the cuttings reach the up-hole end (502) of the auger tube they are forced into the bailings bucket as more fully explained below.

FIG. 6 shows a detailed view of the bottom portion (24) of the core capture tube which contains the core capture device (10). The bottom portion (24) is comprised of an upper connecting section (120) a middle cylindrical section (122) and a lower housing (124). The upper connection section (120) is adapted to connect to the lower portion (50) of the upper portion (26) of the core capture tube (12). In one embodiment of the invention the connection means is a threaded coupling. The middle cylindrical section (122) is adapted to contain a core sample drilled by the drill bit. The lower housing (124) is adapted to house the scoop (125) and scoop activation mechanism. The scoop consists of a first circular plate (126) and a second circular plate (128) in parallel spaced arrangement. Between the two plates is a scoop member (130), a semi-circular member having the same radius as the first and second plates.

The scoop pivots from a first open position to a second closed position around an axis (132). The scoop also incorporates a first lug (134) and an opposite second lug (136) projecting from the first and second side plates respectively. These lugs are adapted to engage the first (114) and second (116) guide-ways respectively of the lower portion of the activation tube (FIG. 5A). The scoop is mounted between a first (140) and second (142) side plate in a pivoting relationship so that the first lug engages the first guide-way and the second lug engages the second guide-way. The axis (132) pivots around pivot points (144) and (146) on the side plates. The side plates are mounted by mounting means in the form of screws or rivets to the flat outside surfaces (148) and (150—not shown) of the lower housing (124).

FIG. 7 shows a first and second side plate (152) of one embodiment of the invention. Each side plate is generally a rectangular plate having each of its corners (154) cut to 45 degrees. There are four apertures (156) for fixing the side plate to the lower housing. A fifth aperture (158) is adapted for mounting the scoop in a pivoting relationship between the first and second side plates. The outline of the scoop is shown as line (160). The guide-way (162) is adapted to accept a lug (134) or (136) in a sliding relationship between a scoop first open position (166) and a scoop second closed position (168). The radius of travel of the lugs is shown by line (170). A first (174) and second (176) alignment pins on the inside face of the side plates are adapted to fit within alignment holes on the outside surface of the lower housing. In operation, the guide ways (114) and (116) (FIG. 5A) are engaged with lugs (134) and (136) respectively. In order to move the scoop from its first open position to its first closed position, the lower portion of the activation tube is moved downwards which rotates the scoop in a clock-wise movement. This causes the scoop to cut the core sample within the lower core capture tube capturing the core in the scoop. To maintain the scoop in the open position, the lower portion of the activation tube is moved upwards so that the guides pull the lugs up and rotate the scoop to its open position. The invention accomplishes this movement of the activation tube by way of a mechanical control system further described below.

FIG. 8 shows the major sub-systems to the mechanical control system used to control the core capture device. These are the wire string (200), the swivel clutch (202), dogging & swivel clutch (204) and the sample collection bucket also known as the bailings bucket (206). The wire string is inserted down-hole through the hollow drill string and is used to activate and de-activate the core sampling scoop and the cuttings management system which includes the bailings bucket and the port controlling entry to the bailings bucket.

The wireline mechanism (200) is an integral part of the entire sample capture device. The wireline delivers the sample capture device to the bottom of the hole and it activates the opening and closing of the sampling scoop. Once the sample capture device is in place, operational sequences allow the wireline to move from controlling the opening and closing of the scoop to opening and closing of the bailings bucket port. Once these operations are complete, the wireline disengages, by means of a clutch mechanism, and allows the sampling device and port opening to rotate freely with the drill string while the wireline stays stationary.

As the drill completes a drilling cycle (has drilled a sample), the wireline re-engages and closes off the bailings bucket ports, thus preventing any loose material entering the inside of the drill string. Following port closure, the wireline re-positions itself to facilitate the closure of the gate on the sample capture device, thus capturing the sample. The sample capturing device is capable of capturing a sample of consolidated or unconsolidated material.

Once the sample has been secured, the wireline hoists the entire bailings bucket and sample capture device mechanism to surface, where the captured sample or cuttings from the bailings bucket may be further processed or disposed of as required.

The wireline is required to:

(1) impart thrust to facilitate the collapse of the spring activated components;

(2) be capable of handling the retraction forces required to break a consolidated sample, release the springs and to lift the core capture device up the drill string;

(3) be flexible enough to allow the wireline to be coiled on surface during retrieval and stowed sequences; and,

(4) be rigid to allow rotational forces to be transmitted when in the extended locked position.

The wireline configuration has a first retracted position and a second deployed position. In its retracted position, the wireline can be coiled onto a spool where it awaits deployment. Once activated, the wireline is pulled off the spool into a deployed position down the drill string. Once the core capture device has contacted the bottom of the hole, the wireline is mechanically locked together by a pin system illustrated herein.

Referring to FIG. 8 and FIG. 9, the wireline comprises a plurality of vertebra-like members (210) serially joined. The individual vertebra-members are shown in FIG. 9 views A to E. Each member has a Y-shaped body (211) composed of a leg member (212) and two arm members (214) and (216). Each of the arm members is composed of a section (218) and (219) angled outwards from the leg member and a straight section (220) and (221) parallel to the leg member. Proximal to, and just above the bottom end (222) of the leg member is a first elongated aperture (224) and a second adjacent elongated aperture (226) adapted to engage a first pin (228) and a second pin (230) in a pivoting and sliding relationship. The first pin and the second pin are located on the inside surfaces (232) and (234) of each of the straight sections (220) and (221). The vertebrae are serially joined by the aforementioned pins and apertures to form the wire line that can be coiled onto a storage drum when not deployed down the drill string. Depending from the bottom end of the vertebra member is a third pin (240) which is adapted to fit within aperture (242) located between the two arm members (214) and (216). In the illustrated embodiment, the vertebra-members include a first (244) and second (246) apertures for weight saving.

Referring to FIG. 8, the wire string has a first compressed operating mode (250) wherein each of the third pins (240) are engaged in their apertures (242) and each of the first (228) and second (230) pins are at their bottom position in the elongated apertures.

FIG. 10 shows a plurality of members in three modes: separated (252), joined and uncompressed (254) and joined and compressed (256).

Referring to FIG. 8, the wireline (200) is connected to an overshot mechanism consisting of the clutch assemblies (202) and (204) adapted to deliver the sampling device to the bottom of the drill string via the wireline and to activate both the bailings bucket port control and the scoop of the sample capture device. In addition, the overshot mechanism must keep the entire sample capture device/bailings bucket at the bottom of the hole and allow them to rotate freely while the wireline remains stationary.

Referring to FIG. 8 and FIG. 11, the wireline (200) is attached to the overshot mechanism (202) by cap member (260). In turn, cap member (260) is fixed by threading on to swivel housing (266). Clutch shaft (270) top end (271) is held to swivel clutch housing (266) by screw (262) and thrust washer (264). In deployment, the wireline is forced down vertically into the drill string thereby compressing its vertebrae together and also compressing swivel spring (268) which will allow the swivel clutch (272) to engage into the swivel clutch housing (266) on shaft (270). A slight rotation may be required to engage the clutch pins (276) tensioned by clutch springs (276). When the swivel clutch assembly is engaged, torque from the wireline (200) can be transmitted through the overshot mechanism to the bailings bucket port control mechanism (204) to open or close the ports to the bailings bucket or to open or close the sampling scoop. When the tension in the wire line is released, the vertebrae disengage from each other to an elongated configuration. The swivel clutch (272) is disengaged by the tension in the spring (268) and the wire line will be stationary while the bailing bucket control mechanism and bailings bucket continues to rotate during drilling operations.

Referring to FIG. 12, the port control mechanism includes an inner port control sleeve (292) and an outer port sleeve (294). The inner port control sleeve nests inside of the outer port sleeve. The wireline (200), dog clutch (285) and swivel clutch (300) control the inner port control sleeve and outer port sleeve so that they move relative to each other in order to open and close the ports as more fully explained below.

Referring to FIG. 12A, the outer port sleeve (294) consists of a tubular body (295) having a top portion (297), a middle portion (299) and a bottom portion (301). The top portion and the middle portion have an inside diameter (305) that is adapted to fit the inner port control sleeve in a sliding relationship. The bottom edge of the inner port control sleeve, when installed into the outer port sleeve, abuts shoulder (307). The middle portion has a plurality of ports (303) adapted to coincide with the ports in the inner port control sleeve so as the inner port control sleeve rotates under the influence of the wire line (200) it is able to close the port access from the inside auger wall to the inside of the bailings bucket. The inside diameter (309) of the bottom portion (301) of the outer port sleeve is adapted to fit the swivel clutch (300).

FIG. 12B, shows two views, A (side view) and B (top view), of the internal port control sleeve (292). The sleeve includes a splined top end (291) that is adapted to mesh with the dogs of the dog clutch (285). Within the sleeve (292) are a first set of ports (311) and a second set of ports (313) below the first set in a parallel relationship.

In operation, active port control is incorporated in the upper section of the auger mechanism and is in the transition zone. Cuttings from the comminution zone migrate to the top portion of the auger with the aid of the fluidizer which is more fully described below. The outer diameter of the port control mechanism above the auger is larger, thereby directing the cuttings into and through the ports to fall into the bucket for transport to the surface. The activation of the port control is completed via the wireline mechanism. During a drilling sequence, the ports are open allowing the cuttings to pass through the port into the bailings bucket. During a bailings bucket extraction cycle, the ports are closed prior to removing the core sampling device and bailings bucket, thus preventing the ingress of contaminants onto the seating area of the sample capture device. Contaminants at the bottom of the hole would prevent the sample capture device from seating properly once it had returned from surface for the next drilling cycle.

Referring now to FIGS. 8,11and 12, the bailings bucket port control mechanism (202) & (204) is shown in greater detail. The bottom (273) of the clutch shaft (270) is in threaded engagement with the top end (281) of the dog clutch activation shaft (282). The shaft (282) is covered by a shaft cover (280). Swivel clutch (272) is attached to the dog clutch activation shaft (282). The wireline is forced down the drill string and this compresses the vertebrae to its compressed mode. In turn, the bailings bucket port control clutch spring (296) and the swivel clutch springs (304) are compressed to engage both the dog clutch (288) and the swivel clutch (300). Rotating the wireline (200) in a clock wise (CW) direction will open the sample capture device scoop and also extend the dogs (285) into the port sleeve splines (291). The wireline (200) will be moved up vertically approximately 15mm until the dogs (285) enter the port sleeve splines (291) and bottom-out on the adapter sleeve shoulder. The swivel clutch (300) will still be engaged allowing the dogging activation shaft (282) to open the port control sleeve (292). When the port control sleeve (292) is open the wireline (200) will move up vertically to a point where the swivel clutch assembly (300) is disengaged. At this point the drilling can be continued.

To capture a sample using the core capture device, the following procedure would be used. The wireline (200) would be forced down vertically until the swivel clutch assembly (204) was engaged. The wireline (200) would then be rotated in a counter clock wise (CCW) direction to close off the port control sleeve (292). When the port is closed off, the wireline (200) would be forced down vertically until the dogs (285) enter the port control sleeve (292) undercut. The wireline (200) would then continue to rotate in a CCW direction until the dogs (285) retracted and the scoop is close off. When the scoop is closed off, the sampling device, bailings bucket, port control and swivel line can then be removed from the drill string.

Cuttings Disposal and the Bailings Bucket

Referring to FIG. 8 and FIG. 13, the bailings bucket (300) is a hollow tube and it is placed in the drill string to collect cuttings being carried up the auger tube (500 FIG. 5C) from drilling operations and dispose of them. The amount of cuttings that will migrate up the auger into the bailings bucket will expand in volume by a factor of up to 4:1. It has been our experience that a 15 mm diameter by 10 cm long consolidated core will need a 40 cm long bailings bucket to hold the amount of cuttings that have migrated up the auger from the comminution zone. Therefore, the volume of the bailings bucket needs to be at least 4 times larger than the sample capture device.

Assuming the above mentioned dimensions, when drilling holes 2 meters in depth, the sample capture device with a 40 cm long bailings bucket will need to be extracted 20 times out of the drill string in order to remove the captured core and cuttings. In addition, the port control will also be subjected to 20 complete cycles from fully open to fully close to ensure the cleanliness of the core capture device seat. Operational decisions will need to be made to determine the quantity of cuttings and or core/sample that will be kept for further processing or analysis. Depending on the quantities of material required for the analysis or process, it is possible that some of the generated cuttings and/or core may be deemed waste material and dealt with accordingly.

Referring to FIG. 13, the bailing bucket (300) is shown in a disassembled view and is composed of a hollow tube (302) having a bottom nut (304) to cap the bottom end (305) of the hollow tube in threaded engagement and a top swivel (306) mounted at the mouth (308) of the bucket (302). The swivel is a “T” shaped member having a stem (310) and a first (312) and second (314) arms. The arms are placed into apertures (314) and (316) in a pivoting relationship. The top end (318) of the stem (310) has a hinge member (320) adapted for pivoting engagement with the bottom end (299) of swivel clutch shaft (298 FIG. 12) by way of apertured member (322). The hinge point (306) above the bailings bucket allows for simple manipulation of the bailings bucket when it reaches surface. The bailings bucket may either be delivered to science experiments or be dumped to a specific location. The hinge permits easy removal of the cuttings from the bucket by allowing the bucket to be tilted and the cuttings dumped.

The sample capture device (10) is connected below the bottom nut (304) so that the bottom section of the bailings bucket is the transition zone between the bucket and sample capture device. The bailings bucket transmits the forces of the wireline directly to the sample capture device for operation of the scoop allowing a sample to be captured.

In FIG. 14, the bailings bucket (300) is shown in assembled views A, B and C. The core capture device is connected by a threaded connection to the internally threaded projection (324).

FIGS. 15 and 16 show details of the anti-contamination wiper (330). The anti-contamination wiper is a flared edged (332) attachment to the top section of the bailings bucket (302). The lip (334) of the anti-contamination is press-fit into the top of the bailings bucket. The flared edge (332) sits directly below the active port control that allows the cuttings to pass through the drill string and fall directly into the bailings bucket. The flared edge prevents the cuttings from falling between the bailings bucket and the internal section of the auger. Each time the entire core capture system is removed from the drill string, the anti-contamination wiper scrapes the entire interior length of the drill string, thus preventing any cuttings from falling onto the seat section for the core capture device. Cuttings or unconsolidated material outside the drill string will tend to slump into the ports. With the active port control mechanism in place, this material will be prevented from entering. When the core capture device re-enters the drill string, cuttings that cling on the bailings bucket or port control mechanism will not fall below the cuttings bucket, because the bucket's anti-contamination wiper sets rides the entire length of the drill string. A second anti-contamination wiper (331) may be located on the bottom of the port control sleeve as illustrated in FIG. 17.

An operating sequence is outlined below for capturing an unconsolidated sample.

-   -   Position the core capture device gate in an open position while         drilling, allowing the sample to enter into the core capture         device.     -   Permit the sample to fill the core capture tube as indicated by         the drill's penetration sensor.     -   Push the wireline into a closed position (collapsed) to transfer         rotational forces to the core capture device gate.     -   Rotate the drill string to drive the outer activation tube down         over the sample tube.     -   Rotate the core capture device gate 90 degrees into the closed         position, closing off the bottom opening and capturing the         sample.     -   Use the wireline to draw the core capture device, sample and         bailings bucket to surface.

The operating sequence for capturing a consolidated (core) sample is outlined below.

-   -   Open the core capture device gate to permit the sample to enter         the core capture tube.     -   Fill the sample tube as indicated by the drill's penetration         sensor.     -   Push the wireline into the closed position (collapsed) to         transfer rotational forces to the gate.     -   Rotate the head clamp of the drill string to drive the outer         activation tube down over the sample tube.     -   Commence to close the core capture device gate until the         predetermined forces are exerted on the gate due to its closure         on a core. Torque sensing is used to ensure that the core         capture device is not damaged if it cannot fully close.     -   Permit the core capture device to rotate freely around the core         so that the base of the core is scored by the gate.     -   Stop the rotation and close the gate in order to snap the core         from the rock base.     -   Commence to close the core capture device gate until the         predetermined forces are exerted on the gate due to its closure         on a core. Torque sensing is used to ensure that the core         capture device is not damaged if it cannot fully close.     -   This cycle continues until the gate is fully closed and the core         sample is freed from its base rock.     -   Once the gate is fully closed, the wireline is used to draw the         core capture device, core sample and bailings bucket to surface.

In experimentation with the core capture device described above, it quickly became evident that as the auger tube became surrounded by the drill cuttings, the ability for the auger to continue to move the cuttings up the flights decreased. The auger no longer effectively transported the cuttings to the cuttings bucket efficiently and tended to pack the cuttings within the flights of the auger. As a result, drill penetration rates dropped significantly. As well, the reaction forces within the device started to climb and there was notable heat generation in the auger zone. A further result of cuttings removal degradation was balling of material on the bit rendering it ineffective.

To prevent bit balling and clumping at the bottom of the drill hole, it was decided that a cuttings fluidization technique was needed. Test results of the fluidizer described herein indicated that it increased the rate of drill penetration by maintaining the cuttings in a fluid state so that the auger could easily remove the cuttings from communition zone to the bailings bucket.

The fluidizer works by transmitting an impact through the drilling device at a specific frequency. A key requirement for the fluidizer was a direct variable frequency impacting device, capable of delivering a blow that would reverberate through the entire length of the drill string to the comminution zone. Previous tests eliminated such concepts as pinging the side of the drill string or having an electric impact drill incorporated into the top of the drill. Additionally, the frequency of the impacts has to be variable, separate and not necessarily proportional to the rotational speed of the drill string. Drilling through several types of test media required different rotational speeds to move the cuttings from the comminution zone to the augers on the bit and up onto the flights of the auger. If the rotational speed combined with the impacts of the fluidizer is insufficient, the cuttings would begin to pack, and render the auger inefficient. The requirement was an electro-mechanical fluidizer capable of providing a significant impact to the drill string without affecting the other drilling components.

FIG. 18 shows an exploded diagram of the fluidizer (500) with a circular bottom housing (502) and a top flat cap (504). The housing (502) consists of a wall (506) and a bottom surface (508). The bottom surface has an aperture (510) adapted to fit an anvil/hammer combination (512) which provides a variable frequency impact to the drill string. The drill string (not shown) fits through the centre (524) of the anvil/hammer combination. The top flat cap (504) includes an aperture (514) adapted to fit over the top (516) of the anvil/hammer combination (512). The anvil/hammer combination (512) is housed within the housing (502) and the top flat cap (504) closes over the top surface (518) of the housing by a plurality of fasteners placed through apertures (520) in the top flat cap (504) and into apertures (522) along the periphery (524) of the housing. Mounted to the top surface (530) of the top flat cap (504) is a motor and drive assembly consists of a motor (532) and a drive shaft (534) having a top portion (536) extending from the motor to a coupler (538) coupling it to a drive shaft bottom portion (540). The drive shaft bottom portion includes a first gear wheel (542) adapted for meshing engagement with a second gear wheel (544). The second gear wheel is fixed to the end of a cam shaft (546) on which a cam (548) is mounted. When the motor is operating, rotational movement is transmitted down the top portion of the shaft, through the shaft coupling and into the bottom portion of the shaft where it is transformed from vertical rotation to horizontal rotation by the gear wheels. Horizontal rotation of the cam shaft commits the cam to engage the bottom surface of the fluidizer hammer (550) thereby raising the hammer upwards. Attached to the top surface of the hammer is a spring (554) that moves freely within the spring housing (556). There is a tensioning nut (560) that can increase or decrease the travel of the spring within the housing thereby adjusting the amount of force that the spring will deliver to the hammer. As the cam rotates on the bottom portion of the fluidizer hammer, the hammer is lifted and the spring is compressed within its housing. At a certain point, the cam will release the hammer and the spring will drive the hammer downwards to contact the anvil (562). This creates an impact that travels down the length of the drill sting located within the centre of the hammer/anvil mechanism thereby permitting fluid motion of cuttings up the auger tube and preventing fouling of the drill bit with cuttings.

FIG. 19 illustrates the circular bottom housing (502) in side view (A) and plan view (B). The housing has the shape of a cylindrical dish consisting of a wall (506) and a bottom surface (508). The aperture (510) in the middle of the bottom surface is adapted to permit passage of the drill string and to mount the anvil/hammer assembly. A first plurality of apertures (570) is adapted to mount the hammer mounts. A second plurality of apertures (572) is adapted to mount the cam mounts. A third plurality of apertures (574) is adapted to mount the flat top plate (504) to the top of the housing. A fourth plurality of apertures (575) is adapted to mount the bottom housing to the drill frame so that percussions from the anvil and hammer travel down the drill string. Dimensions shown on FIG. 19 are illustrative and exemplary only.

FIG. 20,illustrates the flat top cap (504) in a top view (A) and side view (B). The cap is circular having a large first aperture (580) adapted to permit the drill sting passage through the top cap. A second aperture (582) permits passage of the motor shaft and a third aperture (584) permits passage of the spring into the spring housing. A first set of small apertures (586) mounts the motor assembly to the top surface of the top plate, a second set of small apertures (588) mounts the spring housing to the top surface of the top plate and a third set of small apertures (590) mounts the top plate to the housing. The bottom surface (592) of the top plate comprises a flange (594) that seats within the housing wall and provides a tight seal to the housing to prevent dust ingress into the housing.

FIG. 21 shows three views (A, B and C) of the cam (548) mounted to cam shaft (546). The second gear wheel (544) is fixed to a first end (600) of the cam shaft for meshing engagement with the first gear wheel. Referring back to FIG. 18, as the cam rotates it lifts the hammer and then releases the hammer to hit the anvil. The frequency of impacts can be regulated through motor control.

FIG. 22 shows first hinge member (602) identical to second hinge member (604) for holding the hammer in a pivoting relationship to the anvil. The hinge members are fixed to the bottom surface of the housing plate by way of fasteners penetrating the second plurality of apertures (570) in the bottom surface of the housing and the aperture (606) located in each of the hinge members. A pin member (607) is mounted between the hinge members through respective apertures (608) and (610) for mounting the hammer to the hinge. The apertures (608) and (610) are comprised of a bronze bushing (611) fitted within the apertures to bear the load of the hammer in repeated cycles.

FIG. 23 shows plan (A) and elevation (B) views of the hammer (612) with a ring member (614) having a first lug (616) for mounting to the hinges (602) and (604) by way of pin member (606) through hole (607) and a second lug (618), the top surface (620) of which mounts the spring by way of aperture (622), and the bottom surface (624) which provides an engagement surface for the cam. The dimensions shown in FIG. 23 are exemplary and illustrative only.

FIG. 24 shows plan (A) and elevation (B) views of the anvil (630) comprised of a ring member (632), a cylindrical portion (634) disposed above the ring and a flange member (636) disposed below the ring. Within the flange portion are a plurality of apertures (638) adapted to receive fasters for fastening the anvil to the housing bottom surface.

FIG. 25 shows a front view (A) and a side view (B) of a cam bearing block (640) of a pair of bearing blocks (640) and (642) that are positioned on either side of the cam. The bottom of each block is apertured (643) to receive fasteners that fix the bearing blocks to the bottom of the housing through the plurality of apertures (572). The bearing blocks (640) and (642) are apertured (643) to receive the cam axle, and a bronze bushing (644) is inserted into each aperture to bear the load of cam movement and loading over many repetitions of anvil and hammer contact.

FIG. 26 shows a top view (A) and a side cross-sectional view (B) of the spring cap (650) comprised of a flange member (652), a cylindrical spring housing (654) disposed above the flange member and an aperture (656) centered in the top (658) of the spring housing.

Although the description above contains much specificity, these should not be construed as limiting the scope of the invention but as merely providing illustrations of some of the presently preferred embodiments of this invention. Thus the scope of the invention should be determined by the appended claims and their legal equivalents. 

1. A rotary dry drilling system comprising: a. a surface mounted drill having a drill bit and drill bit driving means rotationally connected through a hollow drill string to said drill bit for drilling a bore through rock to obtain a core sample, wherein said drill string has a head and a tail; b. core sample capture means adapted to travel from the head of the drill string to the tail of the drill string to capture the core sample; c. auger means connected to said drill bit for removing cuttings from a comminution zone; d. cuttings fluidization means connected to said head of the drill string to facilitate transport of cuttings from said comminution zone to said auger means; and, e. cuttings management means connected to said drill string for collecting and transporting cuttings to the surface.
 2. The system as claimed in claim 1 wherein said core capture means comprises a rotating gate assembly having a first open position and a second closed position; a core tube adapted to receive a core sample; an activation tube coaxial with said core tube and surrounding the core tube wherein said activation tube is adapted to mechanically engage said rotating gate assembly thereby moving it from said first open position to said second closed position; and, a screw cap adapted to engage the activation tube and transmit rotational movement from the drill motor to the activation tube so that the activation tube is forced into engagement with the gate assembly.
 3. The device as claimed in claim 2 wherein the gate assembly comprises a gate assembly housing fixed to the bottom end of the core tube, said gate assembly housing adapted to house a rotating gate body.
 4. The device as claimed in claim 3 wherein said rotating gate body comprises a first disc and a second disc, wherein said first and second disc each have an axis, and further wherein the first and second discs are co-axial.
 5. The device as claimed in claim 4 wherein the first disc and second disc are jointed by a member between the respective rims of the first and second disc.
 6. The device as claimed in claim 5 wherein the respective outside surfaces of the first and second disc each have fixed thereto a first lug and a second lug.
 7. The device as claimed in claim 6 wherein said first and second disc first lug is mounted between the respective axis of each disc and the respective rim of each disc.
 8. The device as claimed in claim 7 wherein said first and second disc second lug is mounted to the axis of each disc.
 9. The device as claimed in claim 8 wherein said gate assembly housing includes a bottom orifice to accommodate said drill string, a left side orifice and a right side orifice wherein said left and right side orifices are opposite each other, and wherein the gate assembly housing is adapted to receive said gate body.
 10. The device as claimed in claim 9 wherein said gate assembly housing further includes a first mounting plate and a second mounting plate, wherein said first and second mounting plates are fixed over the left and right orifices respectively by fixing means.
 11. The device as claimed in claim 10 wherein the first and second mounting plates each further include a central aperture adapted to receive the first and second disc first lugs and permit rotational movement of the gate body about its axis.
 12. The device as claimed in claim 11 wherein each of the first and second plates respectively further include a first and second arcuate slot, wherein said first and second arcuate slots are adapted to receive the first and second disc second lugs, and further wherein the first and second slots act as guides to guide the gate body from a first open position to a second closed position.
 13. The device in claim 12 wherein the member is adapted to cut the core sample when the gate body is moving from the first open position to the second closed position and enclose the core within the core tube.
 14. The system as claimed in claim 1 wherein said auger means comprises an externally threaded length of hollow drill string axially connected to the drill bit wherein said externally threaded length is adapted to carry cuttings out of said drill bore.
 15. The system as claimed in claim 1 wherein said cuttings fluidization means comprises means for transmitting a shock wave from the top of the head of the drill string to the tail of the drill string.
 16. The system as claimed in claim 15 wherein said means for transmitting a shock wave comprises a housing adapted for mounting proximate to the head of the drill string by way of an aperture through which the drill string passes, wherein said housing comprises a casing having a removeably fixed casing cap for sealing said casing and an inside bottom surface.
 17. The system as claimed in claim 16 wherein the casing is adapted to contain a flapper having a pinned end and a cam end, wherein said pinned end is pivotly pinned to said inside bottom of the casing and wherein said cam end is adapted for cycling up and down at a variable frequency so that on the down stroke said flapper strikes said inside bottom surface of the casing thereby sending a shock wave down the length of the drill string.
 18. The system as claimed in claim 17 wherein said cam end of the flapper is operatively in communication with a cam, wherein said cam rotates on an axis and communicates said up and down cycling motion to the flapper cam end.
 19. The system as claimed in claim 18, wherein the cam is operatively connected to a motor for driving the cam rotationally about said axis.
 20. The system as claimed in claim 19 wherein said motor is a variable speed motor, and wherein said variable frequency of flapper movement is regulated by regulating the speed of the motor.
 21. The system as claimed in claim 20 wherein the cam end of the flapper is spring biased against the cam.
 22. The system as claimed in claim 21wherein the flapper is weighted to provide the correct magnitude of shock wave to the drill string.
 23. The system as claimed in claim 22 wherein the shock wave travels to the tail of the drill string and is transmitted to the auger means and the drill bit causing the vibration thereof and resulting in the fluidization of the cuttings so that they do not clump, ball, clump or bind to the drill bit or auger means.
 24. The system as claimed in claim 1 wherein said cuttings management means comprises: a. a bucket disposed for collecting cuttings from the auger means and transporting the cuttings to the head of the drill string; b. a port for directing cuttings from the auger flights to the bucket wherein said port has an open position and a closed position; c. port control means for moving the port from said open position to said closed position and from the closed position to the open position.
 25. The system as claimed in claim 24 wherein said port control means comprises a tube section incorporated into the upper section of the auger means, wherein said tube section includes a first and a second port oppositely disposed proximate to the bottom of the tube section.
 26. The system as claimed in claim 25 wherein the bottom end of the tube section sits over the top end of the auger so that as cuttings are carried up the auger they are forced through the open ports and into said bucket.
 27. The system as claimed in claim 26 wherein the ports are closed by said port control means so that the bucket can be removed from the bore hole and so that cuttings do not fall into the centre of the bore.
 28. The system as claimed in claim 27 wherein port control means comprises a wireline mechanism having a first deployed configuration and a second stored configuration.
 29. The system as claimed in claim 28 wherein said first deployed position said wireline is adapted to engage the sample capture device and position it in its open position 